Viscosity comparator



'ia mmijlszs 1529 5121 L. R. PRESS? 4 VISCOSI'TY COMPARATOR Filed April21. 1925 INVENTOR. ZJQR- 4 7 BY v , ATTORNEYSL L5. ssrr R. PRIEST, orGAKLAND, ,oeLIsoRN- BEST AVAILAB GOPY s w Pm we. r L Li 7: Q i)visoosrr'r COMPARATOR. Application filed s rn 21, 1923. Serial No.633,749.

To 0. whom it may concern:- accompanying drawings, it being under Be itknown that I, Lnsnrn R. Purser, a stood that the form and constructionof the citizen of the United States. residing at 0211- device asdescribed and illustrated 1s only lend, the countv of Aisinedu and Stateof one embodiment of the invention, and that i 'Luiifcrnia. haveinvented ceituin new and such form and construction maybe varied, fuiIn'iprovements Viscosity Uompzuuto suit the practical requirements ofthe partors,'o1" which the foii'owing is a specificutioular use to whichthe device is to be put,

Without departing from the essential pr1ninvention relatesto means forindi ciples of the invention as set forth in the e the differencebetween the viseosities cleimshereto appended. of two liquids, one or"which. may be taken Referring to the accompanying draws standard. ings:I

he object of my invention is to provide Fig. 1 is a vertical section ofa preferred a simpie and easily operated device for comembodiment of myinvention, taken on the paring the viscosity of 2'. liquid with that ofline 1 1 of Fig. 2.

u knoivn or standard liquid, Within reason Fig. 2 is a, horizontalsection taken on the able limits of accuracy. My invention may li 2-2 fFi 1, I 1 p be ezi'ihod in u .smuii seii-contuined up I th drawings, thereference numeral 1 purstus .1 can made in portable form designates a.reservoir adapted to contain a or uttzicl to any machine or apparatus insupply or" the standard liquid with Which' 'Wi'ilCll is empioycd siiquid Whose viscosity the liquid of unknown viscosity is to becomdesire *ie to measure by comparison pare l. VVithi-n said reservoirare a. pair of known or stanuerd liquid. One such cylinders 2 and 2", ofidentical interior dimy invention is to measure in this incnsions, inWhich are pistons 3 and 3 re the viscosity of tne lubricating oil ofspectively, suid pistons also being identical, l combustion engines.Such oil both in length and diameter. The pistons when carried in theengine crank-case and 3 and 3 are fixed upon rods 4 and 4'recontinuously circulated, as is the common spectively, which passthrough guides 5 and practise in automobile and airplane engines, 5carried'by the upper heads 6 and 6' of is sub ect to dilution byunburned fuel the cylinders, and are connected by the repast thepistons, such diluspective links 7 and 7 with the opposite ends mfinued,will eventually render the or" a horizontal lever 8. Said lever is pivnthe required lubrication of the otully-mountcd at 9 upon the upper endof a e f device embodying guide ro fllO, which is mounted for vertical99 in any convenient poreoiprocutive movement in a guide 11 extumoliilcor cirpisne, the tending through the reservoir 1. ution may be readilyde The guide rod 10 is pivotully connected at of my invention Wili 12with a lever 13, having a handle 14 at one .isclves to those sk'lled endand at the. other end a fulcrum comprising a link 15 pivotallyconnecting said lever *iher object my nvention is to with thereservoir 1. Thus by moving the e purpose hand lever 13 up and down, theguide rod j rugged con- 10, the horizontal lever 8, and the pistons 2-successful operation by and 3 are all caused to move up and down in theuse laboratory together. The guide rod 10 curries a quadunder conditionswhich rent 16, upon which may be inscribed any do the use of the usuallabor-a1 suitable scuie, not shown, adapted to be trav- "rods ordeteru'iiniug viscosity. It clcd over by a pointer l'l fixed to thelever 8 an object my invention to provide for indicating the angularposition of said equalizing the temperutures oi? lever With respect toits normal or l1orizon- "21rd. iiquid and the liquid under test, tailposition.

temperature being necessary The cylinder 2 has an inlet 18 at its lowersrison thi scosities of end,'equipped with a check valve 19, and anoutlet 20 at its upper end, both said inlet and objects in view myinvention said outlet communicating With the interior ["0 ibed withreference to the of the reservoir 1. The cylinder 2 likewise clearances,

on accountof the identical dimensions of the.

' 19', at its lower end, and an outlet valve at its upper end. Saido'utlet communicates, by a has an inlet 18, provided with a check pipe21, with the reservoir or other contam- The istons 3 and 3 are eachprovided with a y-pass which in its preferred form v comprises aclearance, indicated at 26 and 26 respectively, between the peripheriesof said pistons and the walls of their respective cylinders 2 and 2'.These by-passes, or

have the same length and area,

istons 3 and 3' and the cylinders 2 and 2. he piston rods 4 and 4 arepreferably extended below the pistons 3 and 3, and are adapted to abutagainst the lower ends of the cylinders 2 and 2 to limit the downwardmovement 'of said pistons. Their upward movement is limited by contactwith the lower ends of the guides 5 and 5','which are extended into thecylinders for this purpose.

When the pistons 3 and 3 are drawn upwardly, the standard liquid isdrawn from the reservoir 1 into the lower-portion of the cylinder 2through the inlet 18, and the liq,- ui'd to be tested is drawn into thelower portion of thecylinder 2 from the container 22 throu h'the inlet18, the pipes and 23, and t e jacket 24 surrounding the cylinder 2. Atthe same time any 1i uid which may have been in said cylinders 21 ovethe istons is forced out, the standard liquid owing from the cylmder 2into the reservoir 1 through the outlet 20, and the unknown liquidflowing from the cylinder 2 through the outlet 20' andthe pipe 21 intothe container 22. A certain amount of the liquid above the piston ineach cylinder will be forced down past said piston, but on account ofthe relative restriction of the by-pass or clearance around said ,istonand the freedom of the inlet and out et, the amount of liquid thus b-passed is relatively small compared with t e amountdrawn in through theinlet. In practise seyeral successive strokes of the pistons maybe made,by means of the hand ever 13, to insure that the cylinders 2 and Y 2 arecompletely filled with their respective liquids to the exclusion of anypossible entrapped air.

Under these conditions, when the pistons are forced downwardly, theliquids that are tween said trapped within the cylinders 2 and 2 belowsaid-pistons by the check valves 19 and 19, are forced to flow throughthe restricted orifices formed by the clearances 26 and 26 bepistonsand. the cylinder walls, and since t ese orifices or clearapces areidentical in both length and area, the relalines, in

ma am higher rate of flow, will permit its piston to descend morerapidly'than the other piston, and this difference in the rate of travelof the pistons causes the lever 8 to assume an inclined osition, asshown by the dotted ig. 1, such inclination being suitably indicated bythe position of the pointer 17. Thus it will be seen that the positionof the pointer 171indicatesthe comparative vispi ity of the two liquids,and-that this indi- .t1on is entirely independent of the pressufieapplied to the pistons, such pressure being applied equally to bothpistons through the lever 8.

The temperatures of the two liquids within the cylinders 2 and 2 areequalized, thus removing this factor from the indication of theircomparative viscosity. Such equalization of temperature is effected.partly by having both cylinders immersed in the supply of standardliquid, partly by passing the unknowin liquid through the jacket 26around tbs -standard liquid cylinder 2 be fore reaching its own cylinder2, and finally by the fqrm of the by-passes or orifices through whichthe liquids are forced while their rates ,of fiow are being compared.

- These orifices,being in the form of the an- WallSySO thattheirtemperatures may be more readily equalized.

Frictional forces acting on the two pistons are also equalized. Thepiston rod guides 5 and 5 are identical in length and diameter, and thepistons themselves are prevented from rubbing against the cylinder wallspartly by said guides and-partly by the natural tndon'by of the liquidsto form, under pressure, films of equal thickness throughout the entirecircumferences of the annular Icy-passes 26 and 26.

In adapting my invention for use u on an automobile or other similarlyprope led vehicle, for determiningtlie viscosity or degree of dilutionof the engine crank-case oil, the reservoir 1 and its associatedmechanism can be located in any convenient position, as, for example,upon the instrument or control board, and connected by suitableextensions of the pipes 21 and 23 with the oil reservoir 01' crank-caseof the engine, which would correspond with the reservoir 22 describedabove.

It will be apparent to anyone skilled in the art that the device hereindescribed and illustrated may beconsiderably modified in form andconstruction without departing through from the essential principle ofthe invention, which resides in the provision bf a air of orifices ofknown relative areas, -t rough which the two liquids are respectivelyforced, and means for indicating the viscosity differential between saidliquids asdetermined by their relative pressures and rates of flow. inthe specific embodimentof the invention herein illustrated, anddescribed, the orifices are the b passes or clearances 26 and 26' aroundt e pistons 3 and 3, and said pistons, together with their rods 4 and l,the connecting lever 8, and the ointer l7, constitute the means forindicating the viscosity differential of the liquids flowing throughsaid orifices. In thiscase the ratio between the pressures of theliquids is unity, the viscosity difierential being indicated by thecomparative rates of flow, but as these factors are mutually dependent,they must both be considered as entering into the result. The ratiobetween the areas of the orifices, which in the specific case describedis unity, also enters into the result, and must therefore be a knownquantityl. A viscosity comparator comprising a pair of receptaclesrespectively adapted to receive and contain a'supply of standard liquidand a supply of the liquid to be cornpai'ed therewith, each receptaclehaving as sociated therewith an orifice through which the liquidcontained therein may flow, the areas of said orifices bearing a knownrelation to each other; means-forproducing pressure in the liquidscontained within said receptacles to cause said liquids to flow throughsaid orifices; a connection between the pressure producing means of thetwo re,- ceptacles to cause the pressures of the two liquids to bear aknown relation to each other; and means for indicating the viscositydifferential between said liquids as detcrmined by their comparativerates of flow said orifices.

2. A viscosity comparator comprising a pair of receptacles respectivelya apted to receive and contain a supply of standard liquid and a supplyof the liquid to be compared the with, each receptacle having associatedtierewith an orifice through which the liqui'dcbntained therein mayflow, the areas of said orifices bearing a known relation to each other;a movable member within each receptacle, said members being adapted toproduce pressure in the liquids contained within said receptacles tocause said liquids to flow through said orifices; a connection betweensaid members to cause the pressures of the liquids in the tworeceptacles to bear a known relation to each other and means forindicating the viscosity diilercntial between said liquids as determined by their comparative rates of flow through said orifices.

the liquid held by of said rcceptacles;

3. A viscosity comparator comprising a pair of receptacles respectivelyadapted to receive and contain a supply of standard liquid and a supplyof the liquid to be compared therewith, each receptacle havingassociated therewith an orifice through which the liquid containedtherein may flow, the

liquid and a supply of the liquid to be compared therewith, eachreceptacle having associated therewith an orifice through which theliquid contained therein may flow, the areas of said orifices bearing aknown relation to each other; a movable member within each receptacle,said members being adapted to produce pressure in the liquids containedwithin said receptacles to cause said liquids to flow through theirrespective orifices; an exterior connection between said members tocause equal pressures to be produced in the two liquids; and means forindicatin the comparative rates of flow of said liquids through saidorifices,

5. A viscosity comparator comprising a reservoir adapted to hold asupplyof one of the liquids to becompared; a pair of receptacles within saidreservoir respectively adapted to receive and contain a portion of plyof the liquid to be compared therewith, each receptacle havingassociated therewith an orifice through which the liquid containedtherein may flow,thc areas of said orifices bearing other; means forcausing the liquids contained within said, receptacles to flow throughsaid orifices: and means for indicating the viscosity differentialbetween said,

liquids asdetermiued by their comparative pressures and theircomparative rates of flow through said orifices.

6. A viscosity comparator comprising a pair of receptacles respectivelyadapted to receive and contain a supply of standard liquid and a supplyof the liquid to be compared therewith. each receptacle havingassz'iciate d therewith an oritu-o through which the liquid containedtherein may flow, the

areas of said orifices bearing a known relation to each other; a jacketsurrounding one a connection between said jacket and the otherreceptacle whereby the liquid received by said other receptacle is firstpassed through said jacket; -means for causing the liquids containedWithin said receptacles to flow through said orifices;

said reservoir anda sup-' a known relation to each lllt) ceptac 1.0 adated to receive and tained therein may flow,

2'1 received by said other jacket; means for canstial between said aspistons, adapted for and means for indicating the viscosity differentialbetween said liquids as determined by their comparative pressures andtheir comparative rates of fices. 7. A viscosity comparator comprising areservoir adapted to hold a. supply of one of the liquids to becompared; a pair ot eles within said reservoir respectively contain aportion oil the iquid held by said reservoir and asup ply of theliquid'to be compared therewith, each receptacle having associatedtherewith an orifice through which the liquid con-' the areas of saidorifices bearing'a known relation to each other; a jacket surroundingone of said receptacles; a connection and the other receptacle wherebythe liquid receptacle is first. passed through said ing the liquidscontained within said recep tacles to flow through said orifices; andmeans for indicating the viscosity differenliquids as determinedfiby'their comparative pressures and their comparative rates of flow throughsaid orifices;

.' 8. Afviscosity comparator comprising a pair of identical cylinderstor respectively liquid ,to be compared therewith; a piston operating ineach cylinder and adapted for equal passage capacity for imposing equalpressure upon the two differential between the two liquids.

9. A viscosity comparator comprising a pair of identical cylinders-forrespectively holding the standard liquid and the. liquid to be comparedtherewith; means for establishin and maintaining temperature equalitybetween the two liquids; a piston operating in each cylinder and adaptedfor equal passage capacity for each liquid; and means for imposing equal"pressure upon the two pistons, adapted for a difierence in theirrespective rates of travel due to the viscosity differential between thetwo liquids.

. 10. A viscosity comparator comprising a pair of identical cylindersfor respectively holding the standard liquid and the liquid to becompared therewith; a piston operating in each cylinder and adapted forequal passage capacity for each liquid; means'for imposing equal pressure upon the two pistons, adapted for a dili'erence in their respectiverates of travel due to the viscosity differential between the twoliquids; and means for indicating the diflerence between the re spectiverates of said piston travel.

11. A viscosity comparator comprising a air of identical cylinders forrespectively olding the standard li aid and the liquid to be comparedtherewit a piston operatflow through said ori-' between said jacket foreach liquid; and means a difference in their respectiverates of traveldue to the viscosity ing in each cylinder, and fitted therein with anidentical peripheral clearance for the pas sage of the respectiveliquids; and means forimposing equal pressure upon the two pistonsadapted for a difference in their respective rates of travel due to theviscosity equal passage capacity for each liquid; and

means for imposing equal pressure upon the.

two pistons, adapted for a difference in their respective rates oftravel due to, the viscosity differential between thetwo liquids.

13. A viscosity comparator comprising a reservoir adapted to contain asupply of one of the liquids to be compared; a pair of identicalcylinders for respectively receiving and holding a portion of the liquidcon tained within saidv reservoir and a su ply of the liquid to becompared therewith; a piston operating in each cylinder-and adapted forequal passage capacity for each liquid; and means for IIIIPOSII!" equalpressure upon the two pistons, adapted for a difference in theirrespective rates of travel due to the. viscosityjdilferential betweenthe two liquids.

com arator com risin a 14. A viscosity comparator comprising a pair ofidentical cylinders for respectively pared a jacket surrounding one ofsaid cylinders; a connection between said jacket and the other cylinderwhereby the liquid received by said other cylinder is first passedthrough said jacket; a piston operating in each cylinder and adapted forequal passage capacity for each liquid; and means for imposing pistons,adapted for a difference in their re spective rates of travel due to theviscosity differential between the two liquids.

15. A viscosity comparator comprising a reservoir adaptcd to contain asupply of one oi! the liquids to be compared; a pair of identicalcylinders for respectively receiving and holding a portion of the liquidcontained within said reservoir and a supply otthe liquid-to be comparedtherewith; .a jacket surrounding one of said cylinders; a connectionbetween said, jacket and the other cylinder whereby the liquid receivedby said other cylinder is first passed through said jacket; a pistonoperating in each cylinder and adapted for equal passage capacity foreach liquid; and means for imequal pressure upon the two.

ion

receivin 'g' and holding the liquids to be composing equal pressure uponthe two pistons,- adapted for a difference in their respective rates oftravel due to the viscosity differential between the two liquids 16..Aviscosity comparator comprising a pair of independent, identicalcylinders for I'QSPGCUVCLY holding the standard liquid and theliquicl'to be compared. therewith; a pier 17. A viscosity comparatorcomprising a:

air of independent identical cylinders for P *respectiveiy iioldin thestandard liquid and I the liquid to be compared therewith a pistonoperating in each cylinder ancl adapted for equal passage capacity foreachliquid; a lever having its ends respectively connected with thepistons; means for applying pressure centrally to said lever; and anlndicaitor associated with said lever for de noting its angularity dueto the viscosity 20 differential between the two liquids.

In testimony whereof I have signed my name to this specification.

LESLIE R. PRIEST.

